Subcritical dimethyl ether extraction as a simple method to extract nutraceuticals from byproducts from rice bran oil manufacture

• Published in: Scientific reports Vol. 10; no. 1; p. 21007
• Main Authors: Wongwaiwech, Donporn, Weerawatanakorn, Monthana, Boonnoun, Panatpong
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 03-12-2020; Nature Publishing Group
• Subjects: 631/61; 639/638; Byproducts; Chemical extraction; Clean technology; Dietary supplements; Functional foods & nutraceuticals; Humanities and Social Sciences; Low temperature; multidisciplinary; Rice; Rice bran oil; Science; Science (multidisciplinary)
• ISSN: 2045-2322; 2045-2322
• DOI: 10.1038/s41598-020-78011-z

The byproducts of rice bran oil processes are a good source of fat-soluble nutraceuticals, including
γ-
oryzanol, phytosterol, and policosanols. This study aimed to investigate the effects of green technology with low pressure as the subcritical fluid extraction with dimethyl ether (SUBFDME) on the amount of γ-oryzanol, phytosterol, and policosanol extracted from the byproducts and to increase the purity of policosanols. The SUBFDME extraction apparatus was operated under pressures below 1 MPa. Compared to the chemical extraction method, SUBFDME gave the highest content of γ-oryzanol at 924.51 mg/100 g from defatted rice bran, followed by 829.88 mg/100 g from the filter cake, while the highest phytosterol content was 367.54 mg/100 g. Transesterification gave the highest extraction yield of 43.71% with the highest policosanol content (30,787 mg/100 g), and the SUBFDME method increased the policosanol level from transesterified rice bran wax to 84,913.14 mg/100 g. The results indicate that the SUBFDME method is a promising tool to extract γ-oryzanol and phytosterol and a simple and effective technique to increase the purity of policosanol. The study presented a novel technique for the potential use of SUBSFDME as an alternative low-pressure and low-temperature technique to extract
γ-
oryzanol and phytosterol. The combination of transesterification and the SUBFDME technique is a potential simple two-step method to extract and purify policosanol, which is beneficial for the manufacture of dietary supplements, functional foods and pharmaceutical products.